146
ABOV Semiconductor Co., Ltd.
3) Master transmits repeated START condition with not checking ACK signal. In this case, load SLA+R/W
into the I2CDR and set STARTC bit in I2CCR.
After doing one of the actions above, clear to “0b” all interrupt source bits in I2CSR to release SCL line. In
case of 1), move to step 7. In case of 2), move to step 9 to handle STOP interrupt. In case of 3), move to
step 6 after transmitting the data in I2CDR and if transfer direction bit is ‘1’ go to master receiver section.
7. 1-Byte of data is being transmitted. During data transfer, bus arbitration continues.
8. This is ACK signal processing stage for data packet transmitted by master. I2C holds the SCL LOW. When
I2C loses bus mastership while transmitting data arbitrating other masters, the MLOST bit in I2CSR is set. If
then, I2C waits in idle state. When the data in I2CDR is transmitted completely, I2C generates TEND
interrupt.
I2C can choose one of the following cases regardless of the reception of ACK signal from slave.
1) Master receives ACK signal from slave, so continues data transfer because slave can receive more data
from master. In this case, load data to transmit to I2CDR.
2) Master stops data transfer even if it receives ACK signal from slave. In this case, set the STOPC bit in
I2CCR.
3) Master transmits repeated START condition with not checking ACK signal. In this case, load SLA+R/W
into the I2CDR and set the STARTC bit in I2CCR.
After doing one of the actions above, clear to “0b” all interrupt source bits in I2CSR to release SCL line. In
case of 1), move to step 7. In case of 2), move to step 9 to handle STOP interrupt. In case of 3), move to
step 6 after transmitting the data in I2CDR, and if transfer direction bit is ‘1’ go to master receiver section.
9. This is the final step for master transmitter function of I2C, handling STOP interrupt. The STOP bit indicates
that data transfer between master and slave is over. To clear I2CSR, write “0” to I2CSR. After this, I2C enters
idle state.
To Next Page
Loading...
Need help?
General
